Analysis device and analysis method

Abstract

An analysis device optically scans a surface of a substrate to which particles are fixed, detects a pulse wave included in a detection signal obtained from an optical scanning unit when the optical scanning unit scans the substrate, and counts the particles based on pulse interval between two pulse waves each having pulse width less than first reference value determined depending on first pulse width when the optical scanning unit scans a plurality of particles adjacent to each other when the two pulse waves are detected consecutively.

What is claimed is: 
     
       1. An analysis method comprising:
 irradiating laser light onto a surface of a substrate to which particles are fixed, and generating a detection signal based on reflected laser light reflected from the substrate; 
 detecting a pulse wave and a pulse width of the pulse wave included in the detection signal; and 
 counting the particles based on a pulse interval between two pulse waves each having a pulse width less than a first reference value when the two pulse waves are consecutively detected, 
 wherein the first reference value is a sum of a first pulse width and a predetermined value, the first pulse width being a pulse width detected when adjacent ones of the particles are scanned by irradiating the laser light onto the surface, and the predetermined value being 100% to 130% of a jitter value included in the detection signal. 
 
     
     
       2. The analysis method according to  claim 1 , wherein, when the two pulse waves each having the pulse width less than the first reference value are consecutively detected, the counting of the particles includes counting the particles based on a number obtained by dividing the pulse interval between the two pulse waves by the first pulse width. 
     
     
       3. The analysis method according to  claim 1 , wherein the counting of the particles includes determining that a particle count is one when a pulse wave having a pulse width greater than or equal to the first reference value and less than a second reference value is detected, wherein the second reference value is a sum of a second pulse width and the predetermined value included in the detection signal, the second pulse width being a pulse width detected when a particle isolated from other ones of the particles is scanned by irradiating the laser light onto the surface. 
     
     
       4. The analysis method according to  claim 3 , wherein, when the pulse wave having the pulse width less than the first reference value is detected, and subsequently the pulse wave having the pulse width greater than or equal to the first reference value and less than the second reference value is detected, the counting the particles does not include counting the pulse wave having the pulse width less than the first reference value detected first. 
     
     
       5. The analysis method according to  claim 3 , wherein, when a pulse wave having a pulse width greater than or equal to the second reference value is detected, the counting the particles does not include counting the pulse wave having the pulse width greater than or equal to the second reference value.